mk3 golf OBD port

[Doctle Odd]

Ross-Tech: VCDS-Lite: Download

https://www.google.com/maps/d/viewer...8.kMTwqF0PoXwc

[Doctle Odd]

2nd link is for a map showing members of this site with VCDS they will scan your car. Just look for someone near you and send them a private message

[mick01]

Engine temp 80oC
1st fast Idle 2450-2850
CO 0.58 Max - 0.30
HC 51 Pass
Lambda 1.059 Fail - 0.970 - 1.030

2nd fast idle
CO 0.54 Fail max limit 0.30
HC 77 pass
Lambda 1.072 fail

natural Idle
CO 0.36 Pass max limit 0.50

Since that test result I changed the lambda probe for a new NTK one, and it failed again on High CO level, cant remember what the readings were second time as Iv lost the print out. Any advice is welcome. Thanks

[zollaf]

right, the lambda reading is high so it running rich. the cat is not the problem. if the lambda reading was right then i would blame the cat, but since lambda is high, then its got too much fuel going in. first thing to do is to get a computer on it and look for any codes and look at live data. it could be the cts sensor duff and it thinks the car is cold so its bunging too much fuel in. yours sin't obd compliant, but does have full diagnostic capabilities when the right computer is used. you need vcds or a high end computer like a bosch kts or my snap on modis, but they cost thousands.
also, the co on idle is higher than it should be.

[mick01]

Thanks for your comments, the above readings were from its first emissions test. Prior to the second test some days later I fitted a new Lambda probe and a CTS (a known good one), and it failed again, this time on High CO reading (sorry I don't have print out from second test) and as above the CO at idle IS BELOW the max limit. Can I down load this VCDS some where (preferably free) hook up my laptop to the car and run some sort of diagnosis - or is it a specialist job that will cost more than the car is worth?, I would hate this problem to get the better of me! so any further help appreciated Thanks.

[mick01]

thanks I shall look in to that!

[Doctle Odd]

Try replacing the known good CTS with a known new genuine one. Those little buggers cause a lot of issues

[mick01]

Yes, you have a point, I use the term "known good one" in that I had the same emissions issue last year and a new lambda and CTS sorted the problem, since then I changed the thermostat housing and it came with a new sensor and it was used in the first mot emissions test which failed, so I re-fitted the one from last year, but failed again. Dash board temp reads correct at 90oC, although it doesn't mean the CTS is OK, does it have to be genuine VW, or is GSF or euro car parts OK ? I feel as though we are grasping at straws here! Thanks anyway and keep the ideas coming.

[zollaf]

you are grasping at straws until you get it on a computer.

[mick01]

A fair point, but can I down load VCDS from some where, hook up my laptop and run a diagnostic check as iv asked earlier? I don't have the luxury of a few grand's worth of snap on computer as you do.